Commission on Medical Therapies

Ketogenic Diet Basics

The Ketogenic Diet is a treatment option for people with epilepsy – typically for those whose seizures are not controlled with anticonvulsant medications. It is used more commonly in children than adults owing to greater ability to manage diet restrictions in children.

What is the ketogenic diet?

The ketogenic diet is a special high-fat, low-carbohydrate, and moderate protein diet that is carefully controlled. The word 'ketogenic' means that bio-chemical compounds, called ketones, are made in the body (keto = ketone, genic = producing).

The typical ketogenic diet, called the "long-chain triglyceride diet," provides 3 to 4 grams of fat for every 1 gram of carbohydrate and protein. A ketogenic diet “ratio” is the ratio of fat to carbohydrate and protein grams combined. The kinds of foods that provide fat for the ketogenic diet are butter, heavy whipping cream, mayonnaise, and oils.

Although the sum of carbohydrate and protein in the diet have to be restricted, it is necessary to provide adequate amount of protein. It is also very important to prepare the ketogenic diet carefully supervised by a dietician who monitors the child's nutrition.

How does the diet work?

Usually the body uses carbohydrates (such as sugar, bread, pasta) for its fuel but in the ketogenic diet, fats become the primary fuel. Ketones are one of the possible mechanisms of action of the diet.Â There are other theories such as glucose stabilization, adenosine, polyunsaturated fatty acids, and more.

Who is the diet suitable for?

It is recommended for people whose seizures have not responded to several different seizure medicines. It has been used first in some situations, however. It is particularly recommended for those with the Lennox-Gastaut syndrome, but it is also suitable for many different seizure types and epilepsy syndromes, including myoclonic astatic epilepsy, Dravet syndrome, infantile spasms (West syndrome), mitochondrial disorders, GLUT1 deficiency syndrome, pyruvate dehydrogenase deficiency and those with tuberous sclerosis complex.

How to start the diet

Typically the diet is started in the hospital. The child usually begins by fasting or small amount of the diet (except for water) under close medical supervision for 24 hours. The primary reason for admission in most centers is to monitor for any increase in seizures on the diet, treat hypoglycemia and acidosis (which can happen during the start of the diet), monitor and enhance tolerability, ensure all medications are carbohydrate-free, and educate the families to be able to maintain the diet at home.

Does the ketogenic diet work?

Over half of children who go on the diet have at least a 50% reduction in the number of their seizures and in some children (10-15%) even become seizure-free. Although not all children had better seizure control, some had other benefits such as increased alertness, awareness and responsiveness.

How is the diet monitored?

Urine analysis stick is used to monitor the production of the ketones from the diet.Â In addition, every 3 months approximately other labs are done to monitor electrolytes, kidney function, liver function, carnitine, selenium and more.

Are there any side effects of the diet?

A person starting the ketogenic diet may feel sluggish for a few days after the diet is started. Other side effects that might occur include: kidney stones, high cholesterol levels in the blood, vomiting, constipation, slow growth or weight gain, bone fractures, and more.

How is the patient monitored?

Regular follow-ups are usually every 1-3 months to monitor the growth (height and weight), adjustment of the anticonvulsant medications, monitoring seizure history (frequency and type of seizures). Blood and urine tests are performed to make sure there are no medical complications.

The need for other supplements

Because the diet does not provide all the vitamins and minerals found in a balanced diet, the dietitian will recommend vitamin and mineral supplements such calcium and vitamin D, selenium, iron, folic acid, and other B vitamins. Many centers treat children with citrates (e.g. Poycitra K) to prevent acidosis and kidney stones. L-carnitine is also used by many centers.